PSYC 3100 Lecture Notes - Lecture 18: Operational Sex Ratio, Coolidge Effect, Polygynandry

• School: University of Guelph
• Department: Psychology
• Course: PSYC 3100
• Professor: Pat Barclay

Document Summary

Sex = size of gametes (female has larger gametes, eggs while males are smaller, sperm) In females minimal investment is 9mons, for males the minimal parental investment is a lot less time. After insemination, females are unavailable to reproduce again for at least 9mons, but males can under an hour. Have population with a number of females:males: ex. ratio male:female, operational sex ratio: the number of reproductively available men to the number of reproductively available women (male bias) In some species, males invest more in offspring than females (ex. seahorses: after mating, there are more available females (female bias operational sex ratio, also like this for some fish and bird species. One male and one female; polygynandry multiple female and male: males are taller and twice as heavy. Delayed maturity in males (later than females: wait u(cid:374)til (cid:455)ou"(cid:448)e hit pu(cid:271)e(cid:396)t(cid:455) to fight fo(cid:396) fe(cid:373)ales (cid:894)(cid:271)ette(cid:396) odds of (cid:449)i(cid:374)(cid:374)i(cid:374)g(cid:895)